Composite materials or “composites” of interest in this application are generally well-known engineered materials that typically consist of a reinforcement component and a matrix material. To form a composite, at least one reinforcement component and at least one matrix material is required. The matrix material surrounds and supports the reinforcement component to provide an end composite where the reinforcement component and the matrix material remain separate and distinct on a macroscopic level. Together, the reinforcement component and the matrix material produce a composite having properties different from the individual constituent materials. Although composites can be made from fibrous and aggregate-type reinforcement components dispersed in appropriate matrix materials, for example, as in steel/aggregate reinforced cement/concrete, this invention is more particularly focused on the improvement of composites that employ sheet-like reinforcement components.
Composites made from sheet-like reinforcement components are also well-known, and can be created through a variety of molding methods wherein the matrix material is caused to surround and impregnate the sheet-like material before being cured or otherwise solidified to create the composite end product. A cloth of woven carbon fiber filaments is a common sheet-like reinforcement component, and polymers are common matrix materials.
Composites are now commonly used for creating a number of different body structures where high strength and stiffness to weight ratios are the overwhelming design concern. For example, carbon-epoxy composite parts are now commonly used for aircraft body structures, where their high strength to weight ratio directly increases the load carrying capability of a given aircraft. The strength/weight benefits of the composites could not be taken advantage of if stiffness were sacrificed. Whether it is a bicycle, car, boat or aircraft, high stiffness of the overall body is necessary to avoid dynamic problems and achieve peak performance.
While the high strength and stiffness to weight capability of composite materials has been widely used to improve general vehicle performance, there are niche applications where low stiffness is desired. For example, in many circumstances it is desired to structurally mount an aircraft engine and inlets separately to the airframe. This arrangement resolves immediate structural needs of the inlet and engine, but causes a sealing issue at the interface. Inevitably, the engine and inlet will displace differently in response to aircraft loads. To deal with this relative motion, rubber seals have been used, but durability and design problems are plentiful. The relative motion tends to wear out the seals and in worst case scenarios, a seal can be sucked into the engine leading to much bigger problems. Seal designs that are successful tend to require substantial mounting features which have noticeable weight penalties.
For all of these reasons, a better compliant joint is desired. This joint will ideally be structurally incorporated into the existing components without the need of fasteners, flanges or other attachment mechanism which add weight. The invention presented herein, describes a compliant joint and its method of production which satisfies these requirements.